Objectives. To develop and formulate a new experimental dentifrice with and without fluoride based on the peel and the fruit of thePassiflora mollissima(tumbo) and also to evaluate its antimicrobial activity against seven bacterial strains.Methods. The sample was calculated using the mean comparison formula, obtaining wells (n = 12) for each of the strains evaluated:S. mutans,E. faecalis,Actinomyces,Lactobacillus,C. albicans,S. sanguinis, andS. oralis. The antibacterial activity of the dentifrice was evaluated by the direct contact technique.Results. It was found that the highest antimicrobial activity was only present in pulp-based dentifrices against strains ofS. mutans21.0 ± 1.8,E. faecalis16.3 ± 3.9,Actinomyces22.1 ± 1.3, andLactobacillus21.0 ± 1.3. However, in comparison with other strains such asC. albicans,S. sanguinis, andS. oralis, the peel-based dendrifrice ofPassiflora mollissimaobtained the highest antimicrobial activity.Conclusion. The experimental dentifrice based onPassiflora mollissimahad an antibacterial effect against the seven microbial strains during the first 24 and 48 hours.